Toroidal nuclei of columnar lyotropic chromonic liquid crystals coexisting with an isotropic phase

Abstract

Nuclei of ordered materials emerging from the isotropic state usually show a shape topologically equivalent to a sphere; the well-known examples are crystals and nematic liquid crystal droplets. In this...

Topological transformations of a nematic drop

“…Here, C refers to the columnar phase of the DSCG dispersions, in which the chromonic aggregates form a two-dimensional hexagonal periodic lattice in the planes perpendicular to the director nfalse^. The positional ordering of aggregates in the C phase prohibits splay and twist of the director ( 21 ), resulting in toroidal shapes of C nuclei coexisting with the isotropic melt, with a pure bend of the director ( 26 ). The increase of the concentration c inside the N droplets is supported by the measured decrease of the inter-aggregate distances as the temperature raises (Fig.…”

Chiral three-dimensional supramolecular assemblies: colloidal onions, cubosomes, and hexosomes

“…The external shape of hexosomes is that of a truncated cone, while its internal nanostructure consists of hexagonally packed columns. 39–42 The TEM and SEM images in Fig. 3A-3 and Fig.…”

A computational study of nematic core structure and disclination interactions in elastically anisotropic nematics

“…23,24 A possible remedy involves consideration of gradient terms of fourth order in Q. 25 It is also possible to maintain a third order theory, and avoid choosing among fourteen possible fourth order terms allowed by symmetry, by introducing the Ball-Majumdar singular bulk potential method. 23,30 A bulk free energy F b ½Q ¼ E½Q À TDS½Q is defined where E is the bulk energy, T is the temperature, and DS is the entropy relative to the isotropic phase.…”

“…23,24 In principle, the requirement of a bounded free energy could be accomplished by consideration in the expansion defining F el of terms at least of fourth order in Q. 25 However, it is also possible to have a bounded free energy, only third order in Q, by constraining the eigenvalues of Q to lie within their physically admissible range. 23 The resulting singular potential method sidesteps the need to choose between fourteen possible fourth order invariants 26 (in addition to choosing among six possible third order invariants).…”